New AI.dev/CHEATSHEETS/ reference set for delegating to terminal AI agents: - README.md: comparison matrix, 'which CLI?' decision guide, official-docs links, cross-CLI rules + ByteLyst environment facts - devin-cli.md: sessions, --permission-mode dangerous vs --sandbox, resume, the sandbox-stall gotcha, delegation pattern + prompt preamble - claude-code-cli.md: REPL/-p/-c/--resume, permission+plan modes, slash commands, MCP - codex-cli.md: interactive vs codex exec for CI, sandbox x approval matrix, config.toml Flags hedged with 'confirm via --help' since they drift between versions; durable value is the ByteLyst workflow. Does not reference .devin/config.local.json contents.
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🟢 Codex CLI — Cheat Sheet
What it is: OpenAI's Codex CLI — an open-source terminal coding agent that edits files and runs commands inside a built-in sandbox, interactively or as a scriptable one-shot (
codex exec). Best for: Fast local edits, and automation —codex execslots cleanly into CI / Gitea Actions and one-shot scripts. Per-repo rules: readsAGENTS.md(merged with~/.codex/AGENTS.mdand any project-localAGENTS.md). In this repo: delegation examples live underdocs/ecosystem/delegation/codex/anddocs/CODEX_RESUME_PROMPT.md.
⚠️ Flags/modes drift between versions. Confirm with
codex --help.Official docs: https://developers.openai.com/codex/cli · source: https://github.com/openai/codex
Install & auth
npm install -g @openai/codex # or: brew install codex
codex --version
codex login # ChatGPT sign-in, or set OPENAI_API_KEY
- Config & state live under
~/.codex/(notably~/.codex/config.toml).
Launching
codex # interactive TUI in the current dir
codex "add a vitest for src/lib/utils.ts" # seed the first instruction
codex exec "run the test suite and fix failures" # non-interactive one-shot (scripts/CI)
codex resume # resume a previous session
Approval + sandbox modes
Codex couples what it can touch (sandbox) with when it asks (approvals).
| Flag | Meaning |
|---|---|
--sandbox read-only |
Can read; no writes, no commands |
--sandbox workspace-write |
Can edit the working dir + run commands in it (default-ish) |
--sandbox danger-full-access |
No sandbox restrictions |
--ask-for-approval untrusted | on-failure | on-request | never |
When to prompt you |
--full-auto |
Convenience: low-friction auto (workspace-write + minimal prompts) |
--dangerously-bypass-approvals-and-sandbox |
No approvals, no sandbox (CI/throwaway only) |
codex --full-auto # everyday autonomy, still sandboxed
codex --sandbox workspace-write --ask-for-approval on-failure
codex exec --dangerously-bypass-approvals-and-sandbox "..." # CI only, isolated runner
🧠 The sandbox is built in (unlike Devin's optional
--sandbox). For ByteLyst,workspace-writeis fine for single-package work, but cross-packageworkspace:*builds and the corp proxy / Gitea tunnel may need broader access — prefer running from the monorepo root and, if installs fail, loosen the sandbox rather than fighting it.
Config (~/.codex/config.toml)
model = "..." # default model
approval_policy = "on-failure"
sandbox_mode = "workspace-write"
# [mcp_servers.*] # wire external tools via MCP
Project-level AGENTS.md is layered on top of ~/.codex/AGENTS.md.
codex exec for automation (the high-value mode)
# One-shot, non-interactive — perfect for Gitea Actions / scripts:
codex exec "typecheck the repo and fix any TS errors" \
--sandbox workspace-write --ask-for-approval never
- Deterministic, no TUI; exits with a status you can gate CI on.
- Pair with a tight prompt + explicit verify commands (see below).
ByteLyst workflow
Lead with the shared guardrails (Codex reads AGENTS.md, but restate scope):
Follow AGENTS.md + AI.dev/SKILLS/agent-behavior-guidelines.md.
Scope: <paths> only. Tests are sacred. No console.log. productId on Cosmos docs.
Verify: pnpm --filter <pkg> typecheck && ... test && ... build (next build --webpack).
pnpm workspace; @bytelyst/* via workspace:*. Conventional commits, one per change.
Only mark done after verify passes; never fabricate results.
- Start in
read-onlyfor a plan, then switch toworkspace-writeto execute. - Reserve
--dangerously-bypass-approvals-and-sandboxfor the isolated CI runner.
Troubleshooting
| Symptom | Fix |
|---|---|
| "permission denied" writing files | Sandbox is read-only; use --sandbox workspace-write |
Can't build @bytelyst/* deps |
Sandbox can't see sibling packages/* — run from monorepo root, loosen sandbox |
| Network/registry errors | Corp proxy must be active; workspace deps avoid the registry |
next build fails (Turbopack) |
Use next build --webpack |
| Non-interactive run hangs on a prompt | Add --ask-for-approval never to codex exec |
Quick-reference card
codex # interactive
codex "..." # seed an instruction
codex exec "..." # one-shot (CI/scripts)
codex resume # resume session
--sandbox read-only|workspace-write|danger-full-access
--ask-for-approval untrusted|on-failure|on-request|never
--full-auto # convenient autonomy (still sandboxed)
~/.codex/config.toml # defaults: model, approval_policy, sandbox_mode
Related: devin-cli.md · claude-code-cli.md ·
../PROMPTS/ · ../SKILLS/agent-behavior-guidelines.md
Last updated: 2026-05-28 · verify flags against your installed version (codex --help).